This invention relates to a cleaning apparatus and, more particularly, to methods for the autonomous control of such an apparatus.
There is a great deal of current interest in autonomous cleaning devices or robots. With rising janitorial labor costs, increased computer processing power and dropping prices for sensors and electronic hardware, autonomous devices that once would have been too expensive or even impossible are now practical.
U.S. Pat. No. 5,548,511 shows a method for the autonomous cleaning of a floor area, particularly a hallway, and is included herein by reference. To clean larger floor areas, a method employing distance sensors having a longer range than that of sonar (e.g., 5 meters) is desirable. Light wave distance sensors, such as laser distance sensors, can be used over distances greater than those in the largest buildings. These light wave distance sensors have excellent relative distance measuring accuracy, but tend to have poorer absolute distance measuring accuracy. This is due at least in part to the small beam size exhibited by the sensor. The beam can enter relatively small openings or irregularities in the target wall or object and provide misleading distances.